THERESA May has called for an overhaul of the House of Commons disciplinary procedures in the wake of claims of sexual harassment at Westminster.

The Prime Minister has ordered a Whitehall inquiry into whether or not her colleague Mark Garnier, the International Trade Minister, breached ministerial rules after he allegedly used derogatory language to his secretary and asked her to buy sex toys.

Conservative MP Anna Soubry, the former Business minister, has called on John Bercow, the Commons Speaker, to ask for an urgent statement from Andrea Leadsom, the Leader of the House, about what can be done to ensure that any complaints against anybody in Parliament are dealt with properly.

The expectation is that such a statement will be made later today.

Mrs May warned that the Commons disciplinary procedures lacked "teeth" and required urgent reform.

In a letter to Mr Bercow, she said a situation where MPs did not have to follow procedures laid down by the Independent Parliamentary Standards Authority[IPSA] could be tolerated no longer.

She asked for Mr Bercow's assistance in working on a cross-party basis to establish a new "House-wide mediation service" backed by a "contractually binding grievance procedure" available for all MPs.

In her letter Mrs May said she was sure the Speaker would share her concerns at recent media reports of alleged misconduct by some MPs towards staff.

"It is important that those who work in the House of Commons are treated properly and fairly as would be expected in any modern workplace," she wrote.

"As you know, there is a suggested disciplinary procedure provided by IPSA as part of the standard contract. However, it does not have the required teeth as contractually an MP does not have to follow the procedure.

"I do not believe that this situation can be tolerated any longer. It is simply not fair on staff, many of whom are young and in their first job post-education," she stressed.

The PM noted how the Conservative Party had offered MPs a code of conduct on a voluntary basis but that it had no legal standing and was "not fit for its intended purpose".

She urged the Speaker to do all he could to “ensure the reputation of Parliament is not damaged further by allegations of impropriety".

Claims of inappropriate behaviour towards women at Westminster follow in the wake of the allegations about disgraced Hollywood movie mogul Harvey Weinstein.

The probe into Mr Garnier was revealed by Jeremy Hunt, the UK Government’s Health Secretary, who said: "These stories, if they are true, are obviously totally unacceptable."

It is claimed Mr Garnier, 54, admitted asking his then secretary, Caroline Edmondson, to buy two vibrators and calling her "sugar tits" in front of witnesses.

"I'm not going to deny it, because I'm not going to be dishonest. I'm going to have to take it on the chin," the Worcestershire MP is quoted as saying.

Ms Edmondson, who has since left to work for another MP, told the Mail on Sunday he gave her the money to buy the vibrators at a Soho sex shop; one for his wife and one for a woman in his Wyre Forest constituency office.

According to the paper, Mr Garnier described the incident as "high jinks" following a Christmas lunch while he said the "sugar tits" comment was part of an "amusing conversation" referring to the TV comedy Gavin And Stacey,

The minister was said to have conceded that, in the current climate, his actions could been seen as "dinosaur behaviour" but he insisted: "It absolutely does not constitute harassment."

Meanwhile, his Tory colleague Stephen Crabb admitted sending "explicit" messages to a 19-year-old woman he interviewed for a job in 2013, when he was a Welsh minister.

The Scots-born married MP, who was Work and Pensions Secretary, was quoted by the same paper as saying he had been "foolish" but that there had been no sexual contact.